Prostate cancer represents one of the most significant challenges in medicine and public health, facing the US healthcare system today. Its increased diagnosis has lead to a virtual "epidemic of this disease. MRI is uniquely suited to imaging the prostate as it allows excellent visualization of the gland, its boundary, substructure and all surrounding tissues. We have developed both a MR-guided prostate brachytherapy and biopsy program, which utilizes the open 0.5T interventional MRT system. We propose to adapt and translate these programs to meet the major advantages offered by high-field MRI (3T). In the proposed research we plan to apply an interactive comprehensive MR image- guided program for the diagnosis and treatment of localized prostate cancer. This integrated system will allow preoperative and intraoperative MR images of the prostate to be available on-line in the operating room. The challenge is to increase the information content of intraoperative image data by using multimodal features while at the same time preserving the interactivity and the near-real time features of intraoperative imaging, in a closed bore high-field system. But if this can be achieved the precise delivery of treatment to maximize tumor control, and minimize side effects will be achieved and will improve the patients quality of life after treatment.